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Who listed the related formulas of physical pressure and buoyancy one by one, including Rou = m / V, which is not published in textbooks? Don't take too many words to explain in front of me. Just tell me what the physical quantity is. I want to copy and paste it
F floating = g liquid discharge = ρ liquid GV discharge
(row V represents the volume of liquid discharged by the object)
Buoyancy calculation formula: F floating = G-T = ρ liquid GV discharge = f upper and lower pressure difference
When the object floats: F floats = g object and ρ object G object and ρ object
Physics. The relationship between mass, weight, pressure and gravity should be formulated
Mass: a property of an object, usually the amount of material contained in the object. It is the property of an object, so the mass of the same object remains unchanged. M = n * M
Weight: under the action of gravity, the size of the downward and pointing force of an object
Pressure: in physics, pressure refers to the force acting vertically on the surface of an object. The stressed object is the supporting surface of the object, the point of action is on the contact surface, and the direction is perpendicular to the contact surface. When the stressed object is a horizontal plane, pressure (n) = gravity (g). The stressed object is not on the water plane, it is the component force of gravity parallel to the surface of the object
Gravity: the force exerted on an object by the attraction of the earth, g = mg
The formula of mass
1. Mass = density * Volume
2. Mass = gravity / g
3. Kinetic energy = mass * velocity squared / 2
Physical mass formula
E=mc^2
Physical formula g = mg, please explain which three words g, m and G are. It's better to write complete words, especially which word is the last G
Gravity is the force exerted on an object due to the attraction of the earth, which is called gravity. In daily life, the gravity of an object is often referred to as weight. The unit of gravity is n, but the symbol is g. the formula is: g = mg. M is the mass of the object, and G is generally 9.8n/kg
Why f-mg = ma
[because overweight is acceleration upward, such as elevator, because of Mg (G + a) & gt; Mg, when you accelerate up or decelerate down, the pressure on the floor is greater than the gravity. Naturally, f = m (G + a)
When Newton's second law works, what formula should be used? For example, f · cos37-m (Mg-F · sin37 °) = ma
What does the formula FN = Mg + F mean?
Newton's second law formula fhe = ma, where fhe is to analyze the force on the research object, analyze the effect of several forces on the object, and determine the size and direction of each force. On this basis, use mathematical knowledge to find the resultant force of these forces, which is fhe. With fhe, you can solve the problem according to Newton's second law fhe = ma. Your f · cos37-m (Mg-F · sin37 °) is fhe
In FN = Mg + F, FN stands for supporting force, Mg stands for gravity, and f stands for friction (possibly static friction). Supporting force is equivalent to resultant force F, which is only the resultant force of some forces
For your reference only! Do more physics and ask more teachers, you will learn it well!
Formula for calculating mechanical efficiency of pulley
Remember that there seems to be more than one. It's better to use carriage return to separate them. Please add the brackets
Mechanical efficiency of pulley block: (ignoring rope weight and friction)
When used to lift heavy objects: η = wyou / wtotal
=G / n.f
=G object / g object + G motion (g motion is the weight of moving pulley)
=Gh/Fs
When it is used to move objects horizontally (i.e. to overcome friction)
η = F.S object / F.S rope
=F / N. f (F is the friction force on the object, s is the object, s is the distance that the object and the rope move respectively)
What are the pulley formulas?
That's the percentage,
I know it's the useful work divided by the total work. I want the inference formula of W and W
The total efficiency of ghfs = w
It is the ratio of useful work to total work
RELATED INFORMATIONS
- 1. In a bathing beach, the bottom of the water is full of stones. In the process of swimming from deep water to shallow water, the following experience and analysis are reasonable () A. Feet are getting more and more painful because water has less and less support for people. B. feet are getting more and more painful because people are receiving more and more gravity. C. feet don't hurt because people are getting lighter and lighter. D. feet don't hurt because water has more and more support for people
- 2. buoyancy A and B are liquid and solid respectively. The density of liquid a is 1g / cm3, and that of solid B is 0.5g/cm3. When a solid solid (composed of substance B) with a volume of 10-3m3 is put into a container containing enough liquid of substance A, how much buoyancy does the solid solid receive when it is still? How much volume does the liquid displace?
- 3. All formulas of buoyancy Buoyancy knowledge explains all the variant formulas of buoyancy
- 4. The meaning and calculation formula of 1 ＼ G 2. On buoyancy formula
- 5. The formula of buoyancy
- 6. Xiaohua did the experiment of "estimating the value of atmospheric pressure." (1) please complete the following experimental steps. A. push the piston of the syringe to the top of the syringe barrel______ Then seal the small hole of the syringe with a rubber cap. B. fasten the neck of the piston of the syringe with a fine nylon rope so that one end of the rope is connected with the hook of the spring dynamometer, and then pull the syringe barrel horizontally and slowly to the right______ Write it down______ It is equal to the pressure of the atmosphere on the piston, F.C______ , denoted as l, read out the volume V of the syringe, then the area s of the piston=______ Finally, the value p of atmospheric pressure at this time is calculated=______ (write the expression with the measured quantity). (2) in the experiment, Xiaohua used the measuring instrument correctly, and the reading was correct, but she found that there was always deviation in the measurement results, which may be caused by (write two points)______ ．
- 7. Typical problems in junior high school physics
- 8. As shown in the figure, a piece of lead is hung under an inflated balloon with a thin thread, put it into the water, and it is just in a static state somewhere. If some water is slowly released from the bottom, the lead and the balloon () A. Still able to stand still B. move down C. move up D. stand still. It's possible to move up or down
- 9. 1. The buoyancy of a small ball with a volume of 2x10 cubic meters and a volume of negative cubic meters is - Niu if it is completely immersed in water. If half of its volume is immersed in water, the buoyancy is - Niu 2. When the gravity of the metal block is 26.5n and the metal block is suspended by a spring scale and immersed in water, the indication of the spring scale is 16.7n. The buoyancy of the metal block under water is - n 3. An object weighing 4 N, with a volume of 0.5 cubic decimeter, will be completely immersed in water, and the buoyancy it receives is - cow, it will lose weight in water—— 4. If a piece of wood weighs 20n and floats on the surface of the water and is still, the buoyancy of the piece of wood to the water is - Niu 5. An ocean going ship sailed into the Huangpu River from the East China Sea. The ship realized the buoyancy it received
- 10. How is the buoyancy formula derived?
- 11. A course of junior high school physics [pressure and buoyancy], This is the physical simulation of Haidian District in Beijing in 2009 As shown in the figure (a cylindrical container contains a plastic box, in which an iron block floats on the water surface), the cylindrical container with bottom area S1 contains liquid with unknown density. Put a cube metal block with density ρ into the rectangular plastic box with bottom area S2 (the thickness of the plastic box can be ignored), The plastic box floats on the liquid surface (the liquid will not overflow the container), and its immersion depth is H1. If the metal block is taken out of the plastic box, it is tied under the plastic box with thin wire, and put into the liquid, the metal block does not contact the container, and the immersion depth of the plastic box is H2. Cut the thin wire, the metal block will sink to the bottom of the container, and the plastic box floats on the liquid surface, The depth of immersion is H3. If the plastic box is always upright without inclination, the pressure of the liquid on the bottom of the cylindrical container is reduced before and after the thin line is cut? Two supplementary points: 1. The density of the liquid in the container is unknown, and the expression should not contain ρ liquid. 2. The question is how much pressure has been reduced. Not why.
- 12. All the formulas for buoyancy and pressure
- 13. When measuring the density of a small solid object, a physics interest group adopted the following experimental operations: first, the mass mo of the object was measured with a balance; then, a certain amount of water was put into a small beaker, and the total mass M1 of the beaker and water was measured with a balance; then, after the object was tied up with a thin line, the mass M1 of the beaker and water was measured, The object is immersed in the water of the beaker (the water does not overflow and the object does not touch the beaker) by holding a thin line in hand. At this time, the measured value of the balance is m2, as shown in Figure 6 A. The buoyancy of an object in water is MOG B. The buoyancy of an object in water is (m2-ml) g C. The density of the object is Mo / m2-m1 * P water D. The density of the object is Mo / m2-m0 * P water 、 I don't understand at all. I'm going to take the senior high school entrance examination right away. It's really disturbing that I don't understand
- 14. Some questions about buoyancy in junior high school physics 1. A 100 cubic centimeter object is hung under the spring dynamometer. When the object is immersed in water, the indication of the spring dynamometer is 1.7n__ N 2. Put a solid aluminum block with a mass of 27g into a beaker filled with water. When the aluminum block is still in water, the mass of water discharged from the beaker is__ g. Put the aluminum block into a beaker filled with alcohol, and the mass of the discharged alcohol is__ g
- 15. Under what conditions is f floating = ρ liquid GV discharged, under what conditions is f floating = g discharged, f floating = m discharged, G discharged
- 16. The physical meaning of G = 9.8n/kg is______ ．
- 17. What's the meaning of ml / dl? How to read it? What's the difference between ml / dl and Mg / dl
- 18. Conversion of kg and Mg 72kg = 10 to the seventh power mg
- 19. What is Archimedes' formula of buoyancy principle An object is subjected to upward buoyancy, which is equal to the gravity of the liquid displaced by the object!
- 20. Why is the buoyancy equal to gravity when an object floats or floats? The volume of water overflowing during floating is different from that during suspension. Why is the buoyancy the same?